COD is a payment method by which the consignee or receiver of the shipment pays the driver or deliverer of the shipment. In a shipping collect situation, the receiver would simply pay the carrier.

To lure Mary into a trap, Sam says "Bloody Mary" in front of a mirror three times and Mary appears: it's revealed that before Jessica's death, Sam had been having dreams of her being killed in the exact same way as his mother, and that he feels guilty for ignoring what he now thinks were prophetic visions.

As they leave, Dean asks Sam what his secret was, but Sam refuses to tell him. Just then he sees Jessica, standing on a street corner in a long nightgown, before she disappears.